Low temperature triggers physiological and behavioral shifts in adult oriental armyworm, Mythimna separata

Migratory insects display diverse behavioral strategies in response to external environmental shifts, via energy allocation of migration-reproduction trade-offs. However, how migratory insects distribute energy between migration and reproduction as an adaptive strategy to confront temporary low temperatures remains unclear. Here, we used Mythimna separata, a migratory cereal crop pest, to explore the effects of low temperature on reproductive performance, behavior, and energy allocation. We found that the influence of low temperatures on reproduction was not absolutely negative, but instead depended on the intensity, duration, and age of exposure to low temperature. Exposure to 6°C for 24 h significantly accelerated the onset of oviposition and ovarian development, and increased the synchrony of egg-laying and lifetime fecundity in 1-day-old adults compared to the control, while female's flight capacity decreased significantly on the first and second day after moths were exposed to 6°C. Furthermore, the abdominal and total triglycerides levels of females decreased significantly from exposure to low temperature, but their thoracic triglyceride content was significantly higher than the control on the third and fourth day. These results indicated that low temperatures induced M. separata to reduce energy investment for the development of flight system. This resulted in the shifting of moths from being migrants to residents during the environmental sensitive period (first day post-emergence). This expands our understanding of the adaptive strategy employed by migratory insects to deal with low temperatures and aids in the management of this pest species in China.

Landscape Characteristics Affecting Small Mammal Occurrence in Heterogeneous Olive Grove Agro-Ecosystems

Understanding how small mammals (SM) are associated with environmental characteristics in olive groves is important to identify potential threats to agriculture and assess the overall conservation value and functioning of agro-ecosystems. Here, we provide first insights on this topic applied to traditional olive groves in northeast (NE) Portugal by assessing the landscape attributes that determine SM occurrence, focusing on one species of conservation concern (Microtus cabrerae Thomas 1906) and one species often perceived as a potential pest of olives (Microtus lusitanicus Gerbe 1879). Based on SM genetic non-invasive sampling in 51 olive groves and surrounding habitats, we identified seven rodent species and one insectivore. Occupancy modelling indicated that SM were generally less detected within olive groves than in surrounding habitats. The vulnerable M. cabrerae reached a mean occupancy (95% CI) of 0.77 (0.61–0.87), while M. lusitanicus stood at 0.37 (0.24–0.52). M. cabrerae was more likely to occur in land mosaics with high density of agricultural field edges, while M. lusitanicus was more associated with high density of pastureland patches. Overall, our study suggests that the complex structure and spatial heterogeneity of traditionally managed olive grove agro-ecosystems may favor the occurrence of species-rich SM communities, possibly including well-established populations of species of conservation importance, while keeping potential pest species at relatively low occupancy rates.

Occurrence and distribution of lace bug, whitefly, and shoot fly pest species on cassava (Manihot esculenta) crops according to region in Paraná State, Brazil

The cassava (Manihot esculenta Crantz) crop is relevant for human livelihoods, particularly in poorer regions. It is consumed fresh or as industrialized flour, and the roots and aerial parts are also used to feed livestock. Pests may limit cassava production, which may endanger food security due to the socioeconomic importance of the crop. Reports of the occurrence of three insect guilds, lace bugs, shoot flies, and whiteflies have been recorded in Paraná State, Brazil, but the distinct species and their distribution are yet to be determined. This lack of information limits the development of strategies to mitigate pest damage. Surveys were conducted in 39 counties (four farms per county) distributed throughout the state that encompass the various socioeconomic regions. The collected material was properly packed and sent to the laboratory for identification, and the following species were identified: lace bugs Vatiga illudens Drake, 1922 and Vatiga manihotae Drake, 1922 (both Hemiptera: Tingidae); whiteflies Bemisia tuberculata (Bondar, 1923) and Aleurothrixus aepim (Goeldi, 1886) (both Hemiptera: Aleyrodidae), and the cassava shoot fly Neosilba perezi Romero & Ruppel, 1973 (Diptera: Lonchaeidae) in Paraná State. Lace bugs were not found in the samples in the eastern and southern portions of the state. V. illudens was more widespread than V. manihotae. The whitefly A. aepim was not observed in three counties (eastern, southern, and central regions), whereas B. tuberculata and the cassava shoot fly were found in all regions sampled in Paraná State. Suggestions for future investigations of pest management are proposed.

Vine Weevil, Otiorhynchus sulcatus (Coleoptera: Curculionidae), Management: Current State and Future Perspectives

Vine weevil, also known as black vine weevil, Otiorhynchus sulcatus, has been one of the most economically important pest species of global horticultural crops for the past five decades. This period has seen many changes in crop protection practices, including wide-scale adoption of biological controls such as entomopathogenic nematodes and fungi in place of conventional synthetic insecticides. Despite the experimental efficacy of these controls, growers continue to report significant crop losses associated with vine weevil infestation. We argue that simply switching from synthetic insecticides to biological controls, rather than using these controls as part of an integrated management program, is a key factor in the continued importance of this pest. An improved understanding of vine weevil biology and ecology is at the center of the development of truly integrated pest management programs. To this end, we identify opportunities created through recent vine weevil research and highlight key knowledge gaps in which further research may contribute to improved future management approaches.

Population differences and domestication effects on mating and remating frequencies in Queensland fruit fly

Females of many insect species are unreceptive to remating for a period following their first mating. This inhibitory effect may be mediated by either the female or her first mate, or both, and often reflects the complex interplay of reproductive strategies between the sexes. Natural variation in remating inhibition and how this phenotype responds to captive breeding are largely unexplored in insects, including many pest species. We investigated genetic variation in remating propensity in the Queensland fruit fly, Bactrocera tryoni, using strains differing in source locality and degree of domestication. We found up to threefold inherited variation between strains from different localities in the level of intra-strain remating inhibition. The level of inhibition also declined significantly during domestication, which implied the existence of genetic variation for this trait within the starting populations as well. Inter-strain mating and remating trials showed that the strain differences were mainly due to the genotypes of the female and, to a lesser extent, the second male, with little effect of the initial male genotype. Implications for our understanding of fruit fly reproductive biology and population genetics and the design of Sterile Insect Technique pest management programs are discussed.

Determinants of Insecticide Resistance Evolution: Comparative Analysis Among Heliothines

It is increasingly clear that pest species vary widely in their propensities to develop insecticide resistance. This review uses a comparative approach to analyze the key pest management practices and ecological and biochemical or genetic characteristics of the target that contribute to this variation. We focus on six heliothine species, three of which, Helicoverpa armigera, Heliothis virescens, and Helicoverpa zea, have developed resistances to many pesticide classes. The three others, Helicoverpa punctigera, Helicoverpa assulta, and Helicoverpa gelotopoeon, also significant pests, have developed resistance to very few pesticide classes. We find that host range and movement between alternate hosts are key ecological traits that influence effective selection intensities for resistance. Operational issues are also critical; area-wide, cross-pesticide management practices that account for these ecological factors are key to reducing selection intensity. Without such management, treatment using broad-spectrum chemicals serves to multiply the effects of host plant preference, preadaptive detoxification ability, and high genetic diversity to create a pesticide treadmill for the three high-propensity species.Without rigorous ongoing management, such a treadmill could still develop for newer, more selective chemistries and insecticidal transgenic crops.

One Bat’s Waste is Another Man’s Treasure: A DNA Metabarcoding Approach for the Assessment of Biodiversity and Ecosystem Services Using Bat Faeces

Arthropod populations are constantly changing due to changes in climate and the globalisation of trade and travel. Effective and diverse monitoring techniques are required to understand these changes. DNA metabarcoding has facilitated the development of a broad monitoring method to sample arthropod diversity from environmental and faecal samples. In this study, we applied DNA metabarcoding to DNA extracted from bat faecal pellets of Rhinolophus hipposideros, the lesser horseshoe bat in Ireland, a highly protected bat species of conservation concern in Europe. From as few as 24 bat faecal pellets, we detected 161 arthropod species, spanning 11 orders, including 38 pest species of which five were determined to be priority pests, highlighting important ecosystem services. We also report the identification 14 species not previously reported in Ireland, but upon further investigation found that many of these are likely misidentified due to inadequacies in the genetic reference database. For the first time, we were able to use non-invasively collected bat samples to examine the role of sex in the diet of bats and found that the male and female diets did not differ significantly. However, sampling location did explain variation within the diet, highlighting how landscape features influence arthropod composition and diversity. We discuss the current limitations of the methodology in Ireland, how these can be overcome in future studies, and how this data can be used for biodiversity monitoring and informing conservation management of protected bat species.

Problems with the Concept of “Pest” among the Diversity of Pestiferous Thrips

Almost all of the thrips species that are considered pests are members of a single subfamily of Thripidae, the Thripinae, a group that represents less than 30% of the species in the insect Order Thysanoptera. Three of the five major Families of Thysanoptera (Aeolothripidae, Heterothripidae, Melanthripidae) are not known to include any pest species. The Phlaeothripidae that includes more than 50% of the 6300 thrips species listed includes very few that are considered to be pests. Within the Thripidae, the members of the three smaller subfamilies, Panchaetothripinae, Dendrothripinae and Sericothripinae, include remarkably few species that result in serious crop losses. It is only in the subfamily Thripinae, and particularly among species of the Frankliniella genus-group and the Thrips genus-group that the major thrips species are found, including all but one of the vectors of Orthotospovirus infections. It is argued that the concept of pest is a socio-economic problem, with the pest status of any particular species being dependent on geographical area, cultivation practices, and market expectations as much as the intrinsic biology of any thrips species.

Food habits of indian crested porcupine (Hystrix indica) (Kerr 1792), in district Bagh, Azad Jammu and Kashmir

The Indian Crested Porcupine (Hystrix indica) is classified as an agricultural pest species. It feeds on plants and crops; hence, it is responsible for massive financial losses worldwide. The current study was conducted to assess the diet composition of Indian Crested Porcupine in District Bagh, Azad Jammu and Kashmir (AJ&K). Thus, fecal samples were collected and examined from different sampling sites. Reference slides of the material collected from the study area were prepared for identification of dietary components in fecal pellets. A total of 80 fecal samples were collected and processed. Percent relative frequencies (P.R.F.) were calculated for each plant species recovered from pellets. Data revealed that Indian Crested Porcupine consumed 31 plant species in its diet, among them Zea mays (34.31±7.76) was the most frequently selected species followed by Rumex obtusifolius (15.32±2.57) and Melia azedarach (12.83±4.79). The study revealed that the greatest diversity of (n=20) plant species were consumed in summer season while minimum (n=13) species were used during winter. Among the parts of plants, stem was highly consumed in spring (57.2%) as compared to seed in fall (36.7%) while spikes and leaf were the least recovered parts from the fecal matter. The Berger-Parker diversity index showed highly diversified food (10.92) in the summer time of the year as compared to the autumn season (2.95). This study provides a baseline for the diet preference of this pest in the study area. Based on current findings, a detailed investigation on damage assessment, exploration, habitat use and management of Indian Crested Porcupine in AJ&K has been recommended.