Among environmental factors, temperature has a direct and crucial influence on the key life processes of survival, development, reproduction, and movement of poikilothermic animals and hence their population dynamics. The lower and upper temperature thresholds and optimal temperature have ramifications for all major life processes, where within a specific range, a temperature change results in a proportional rise or fall of the rate of any given process. There are some basic approaches for modeling development response to temperature in arthropods. The oldest and most widely used model is a simple linear description of arthropod development in relation to temperature. The linear model forms the basis of the well-known thermal summation or degree-day (DD) approach to timing prediction. The second approach for predicting arthropod development rate is nonlinear mathematical models. However, given the fundamental role of thermal models in forecasting and integrated pest management programs, the main purpose of this paper was to facilitate the use of thermal models to estimate the developmental response of arthropods to temperature and select the appropriate model with a view to goodness-of-fit and generalizability by designing a user-friendly software. In this paper, the linear and most common nonlinear thermal models and the main criteria for selecting appropriate models are also reviewed.

Although cultivated and degraded lands outnumber natural ecosystems in many regions of the world, there are relatively few studies focusing on their biodiversity. Here, we investigated the drosophilid assemblages recorded in eight Brazilian fig plantations and discussed probable invasive species among the identified fauna. Each plantation was sampled monthly, from September 2010 to August 2011, using five drosophilid retention traps arranged in an 80-m transect. The 125,428 drosophilids captured represent 52 nominal and 10 unidentified species belonging to eight genera: Diathoneura Duda, Drosophila Fallén, Neotanygastrella Duda, Rhinoleucophenga Hendel, Scaptodrosophila Duda, Scaptomyza Hardy, Zaprionus Coquillett, and Zygothrica Wiedemann. Besides this rich diversity, our samples were dominated by widespread generalists representing exotic and neotropical species: Zaprionus indianus Gupta, Drosophila simulans Sturtevant, Scaptodrosophila latifasciaeformis (Duda), Drosophila sturtevanti Duda, Drosophila mercatorum Patterson and Wheeler, Drosophila cardini Sturtevant, and Drosophila buzzatii Patterson and Wheeler. These species should be carefully monitored, especially in the first half of the year, to prevent environmental and economic losses due to their eventual introduction in new areas.

Eogystia hippophaecolus is a major borer pest of sea buckthorn in China, damaging the environment and sea buckthorn industry. It is widely distributed in the Three-North region of China, and its larvae are resistant to low temperatures. Because heat-shock protein 70 can repair misfolded proteins under low temperatures, thus preventing cell damage and improving tolerance, we investigated the adaptation of E. hippophaecolus HSP70. We screened the transcriptome of E. hippophaecolus for HSP70 homologs, identified a full-length gene, and cloned to obtain the open reading frame, which was 1896 bp in length and encoded 631 amino acids, with a molecular weight of 69.7 kDa. The amino acid sequence contained three signature sequences of the HSP70 family and a C-terminal cytoplasmic character sequence. A phylogenic tree demonstrated that EhHSP70 has high homology with HSP70 genes from other insect species. We measure expression of the HSP70 gene across tissues when larvae of E. hippophaecolus were cold shocked. We also measured expression during cold shock recovery. EhHSP70 expression varied across tissues at 25 °C, with the highest expression in the midgut. Compared with the control, the expression of EhHSP70 in the cuticle was fourfold higher after a cold shock of — 5 °C for 1 h. EhHSP70 expression was also significantly increased during the 1-h period following recovery from cold shock, then decreased. In summary, cold shock promoted the expression of EhHSP70, which may play an important role in the adaptation mechanism of cold tolerance in E. hippophaecolus larvae.

Extensive rearing of monarch larvae (Danaus plexippus L.) through the citizen science Monarch Larva Monitoring Project (MLMP) revealed that monarchs' primary parasitoids are flies in the family Tachinidae and that these parasitoids result in appreciable larval mortality. We document the tachinid community that attacks monarchs in the United States, evaluate their relative frequency, and examine variation in their specificity, oviposition strategy, and use of host stages. Based on results of rearing >20,000 monarchs by MLMP volunteers, overall parasitism by tachinids across life stages was 9.8% (17% for monarchs collected as fifth instars). We identified the flies that emerged from 466 monarch hosts, and found seven Tachinidae species. In decreasing order of frequency, these included Lespesia archippivora (Riley), Hyphantrophaga virilis (Aldrich & Webber), Compsilura concinnata (Meigen), Leschenaultia n. sp., Madremyia saundersii (Williston), Lespesia sp., and Nilea erecta (Coquillett). Lespesia sp., Leschenaultia n. sp., and N. erecta had not been previously reported as monarch parasitoids, and Leschenaultia n. sp. is apparently undescribed. We include new state records (Texas and Iowa) for C. concinnata. Lespesia archippivora and C. concinnata were overrepresented as parasitoids of later instars and were absent from monarchs collected as eggs, but H. virilis and Leschenaultia sp., which lay their eggs on foliage, were reared from caterpillars collected as eggs. To our knowledge, we include the first report of multiparasitism of monarchs, in which more than one parasitoid species emerged from a host. The biology of the tachinid parasitoids we identified and their relationship with monarchs is examined.

The Antheraea mylitta (Drury) (Lepidoptera: Saturniidae) is a commercially important species for the production of tasar silk. However, the Xanthopimpla pedator (F.) (Hymenoptera: Ichneumonidae) is a major pupal endoparasitoid of A. mylitta, which affects the total tasar silk production in India. A gravid female X. pedator parasitizes the pupae of A. mylitta by depositing an egg, which produces a single offspring per host. We studied the development of immature forms of X. pedator by dissecting parasitized pupae of A. mylitta under laboratory conditions at 28–30 °C and 40–60% relative humidity. All immature stages of the parasitoid develop within the host in 20–22 d, by devouring the entire pupal content, resulting in dead or seedless cocoons. The total life cycle of X. pedator is completed inside the host pupa and the adult emerges out by rupturing the peduncle end of the cocoon. During development of X. pedator, five preimaginal stages, viz., egg, larval instars, prepupa, pupa, and a pharate adult, were observed. Xanthopimpla pedator passes through five larval instars identified by structural and morphometric variations. These include primary larva (L1), the intermediate larvae (L2–L4), and the final-instar larva (L5). Biometric study and larval head width permitted the morphological separation of all five larval instars. In the present study, the biology and development of X. pedator inside the pupa of A. mylitta are reported for the first time with detailed photomicrographs. Therefore, the study may enable the information concerning physiological interactions between A. mylitta and its endoparasitoid, X. pedator.

Rhynchophorus ferrugineus (Olivier; Coleoptera: Dryophthoridae) is a pest of many crop and ornamental palm tree species in subtropical regions worldwide. Larvae tunnel and feed unseen in the trunks, ultimately causing irreparable harm and killing the palm. Beauveria bassiana (Balsamo-Crivelli; Hypocreales: Clavicipitaceae) Vuillemin is under evaluation as a biological control agent for R. ferrugineus management but its effects are difficult to monitor under field conditions except by acoustic methods. Older (>30 d) larvae treated with B. bassiana display statistically significant reductions in acoustic activity in semi-field studies, but activity of younger larvae has been more difficult to analyze due to their short-duration cycles of increasingly active and then less active feeding and movement, followed by inactive molting. A procedure was developed to characterize effects of B. bassiana treatments by subdividing long-term recording periods into activity cycles. Treatment effects were compared within and across cycles. The procedure demonstrated statistically significant differences among acoustic activity rates over time for 15-d-old larvae exposed to control, 10⁴, or 10⁸ conidia ml^–1B. bassiana treatments. The results suggest that acoustic technology has considerable utility for monitoring of larval development and for evaluating efficacy of pest management treatments in environments where the targeted insect pests are hidden from view.

The developmental times of poikilotherms at different stages are significantly affected by temperature. Most mathematical models describing the temperature-dependent developmental rates of poikilotherms are built according to the experimental data at various constant temperatures. However, these models can also be applied to the developmental rates at variable temperatures. It is more meaningful to use models to predict the occurrence times of pest insects that actually represent the completion for a particular developmental stage (e.g., hatching, pupation, eclosion) under a natural thermal environment. For some developmental stages, insects might experience a period of high temperatures. In this case, skewed bell-shaped nonlinear models are more reasonable than the linear and exponential models because in the high-temperature region the developmental rate decreases with temperature increasing. We used the accumulated developmental progress method that combines three representative nonlinear models to compare the model validity in predicting the egg's earliest hatching date of bamboo locust in different years. We found that for the springtime phenological event the simple Arrhenius' equation obtains the best goodness of fit. This study also provides a general R function that permits users to employ nonlinear parametric models to predict the occurrence times of insect phenology. In fact, if the investigation data cannot reflect the temperature-based phenological models proposed here, we have to consider whether the data set is reliable or whether the temperature is the crucial factor that determines the occurrence time of interest. The present study is valuable for the integrated management of pest insects because the biological or chemical control timing relies on the prediction on the occurrence time of phenological events.