Temperature shapes oviposition site selection and post-oviposition egg transport in an insect with parental care

Depositing eggs in an area with adequate temperature is often crucial for mothers and their offspring, as the eggs are immobile and therefore cannot avoid exposure to sub-optimal temperatures. However, the importance of temperature on oviposition site selection is less clear when mothers have the capability to avoid these potential adverse effects by both moving their eggs after oviposition and providing other forms of egg care. In this study, we addressed this question in the European earwig, an insect in which mothers care for the eggs during several months in winter and often move them during this period. Using 60 females from two Canadian populations (St John's and Harvey station) set up under controlled thermal gradients, we demonstrated that earwig females both select oviposition sites according to temperature and move their eggs after oviposition to reach warmer environmental temperatures. While this set of behavioural thermoregulation is present in the two studied populations, its modality of expression was population-specific: St John's females explored greater ranges of temperatures before oviposition, laid their eggs in warmer areas, and moved their eggs quicker toward warm locations. Overall, our study reveals that earwig females have evolved both pre-and post-oviposition behavioural strategies to mitigate the risks inherent to tending eggs during winter. More generally, it also reveals that egg care and egg transport do not prevent behavioural thermoregulation via oviposition site selection and highlights the diversity of behaviours that insects can adopt to enhance their tolerance to global climate change.

Analisis Kelayakan Finansial Pembuatan Pakan Ternak dari Sampah Organik Dapur

Cultivation of maggot BSF is an activity in which a person performs maintenance of maggot ranging from egg care, maggot enlargement, hatching pre-pupae into flies, to feeding poultry using maggot. Maggot cultivation is usually carried out in places close to landfills or markets that produce organic waste. This type of BSF maggot is trending because of the protein content in maggot. The objectives of this study are: Analyzing the feasibility of BSF maggot cultivation business based on financial and non-financial aspects. This research was conducted at PPM BSF Dadali Kali Baru, Medan Satria, Bekasi City. The selection of research locations is done intentionally (purposive). The data used in this study are primary and secondary data, where primary data is obtained through interviews and observations. Secondary data obtained through literature, journals, previous research, and books. Data and information that have been collected are analyzed quantitatively which is processed by Microsoft Excel 2013. Financial feasibility analysis is done by calculating IRR, NPV, B / C ratio, BEP, and also Payback Period. The results of this study are: R / C Ratio value of 2,257, B / C Ratio value of 1,237, Volume BEP obtained value of 53.17 kg, BEP Price value of Rp 13,292, Payback Periods (PP) within 4 months 9 days (5 periods), so it can be concluded that Kang Mis's business is feasible to run.

Alteration of gut microbiota with rifampicin does not impair maternal care in the European earwig

ABSTRACTThe microbes residing within the gut of an animal host often maximise their own fitness by modifying their host’s physiological, reproductive, and behavioural functions. Whereas recent studies suggest that they may also shape host sociality and therefore have critical effects on animal social evolution, the impact of the gut microbiota on maternal care remains unexplored. This is surprising, as this social behaviour is widespread among animals, often determines the fitness of both juveniles and parents, and is essential in the evolution of complex animal societies. Here, we address this gap in knowledge by testing whether life-long alterations of the gut microbiota with rifampicin - a broad-spectrum antibiotic - impair the expression of pre- and post-hatching maternal care in the European earwig, an insect exhibiting extensive forms of maternal care towards eggs and juveniles. Our results first confirm that rifampicin altered the mothers’ gut microbial communities and revealed that the composition of the gut microbiota differs before and after egg care. Contrary to our predictions, however, the rifampicin-induced alterations of the gut microbiota did not modify the expression of pre- or post-hatching care. Independent of maternal care, rifampicin increased the females’ feces production and resulted in lighter eggs and juveniles. By contrast, rifampicin altered none of the other 23 physiological, reproductive and longevity traits measured over the females’ lifetime. Overall, these findings reveal that altering the gut microbiota does not necessarily affect host sociality. More generally, our results emphasize that not all animals have evolved a co-dependence with their microbiota.

How to escape from insect egg parasitoids: a review of potential factors explaining parasitoid absence across the Insecta

The egg is the first life stage directly exposed to the environment in oviparous animals, including many vertebrates and most arthropods. Eggs are vulnerable and prone to mortality risks. In arthropods, one of the most common egg mortality factors is attack from parasitoids. Yet, parasitoids that attack the egg stage are absent in more than half of all insect (sub)orders. In this review, we explore possible causes explaining why eggs of some insect taxa are not parasitized. Many insect (sub)orders that are not attacked by egg parasitoids lack herbivorous species, with some notable exceptions. Factors we consider to have led to escape from egg parasitism are parental egg care, rapid egg development, small egg size, hiding eggs, by e.g. placing them into the soil, applying egg coatings or having thick chorions preventing egg penetration, eusociality, and egg cannibalism. A quantitative network analysis of host–parasitoid associations shows that the five most-speciose genera of egg parasitoids display patterns of specificity with respect to certain insect orders, especially Lepidoptera and Hemiptera, largely including herbivorous species that deposit their eggs on plants. Finally, we discuss the many counteradaptations that particularly herbivorous species have developed to lower the risk of attack by egg parasitoids.

Reproductive behavior and larval development of the striped blenny Meiacanthus grammistes

This study aims to describe aspects of reproductive behavior and larval development for the striped blenny, Meiacanthus grammistes. Altogether 8 broodstock fish (8.5 cm to 10 cm) were maintained in two 400 l tanks. The first spawning occurred 45 days in one tank and 65 days in another tank after fish acquisition. Egg clutches were only found attached to inside walls of the 50 mm capped PVC pipes with a single 25 mm reduce entry hole while the male took full responsibility for egg care. The fish spawned routinely every 8–10 days in both tanks throughout experimental period. The fecundity ranged from 500–4,200 eggs per spawning with an average of 1837 ± 1197 eggs/clutch. Newly extruded eggs were spherical and incubation period lasted 203–207 h at 27 ± 1oC. Newly hatched larvae measured 3.11 ± 0.14 mm in standard length (SL) and 0.87 ± 0.08 mm in body depth (BD) with average mouth-gape height and width at 272.42 ± 61.03 µm and 187.50 ± 36.46 µm, respectively. Under such a feeding regime, most of larvae had settled out water column onto the bottom around 23 DPH but not yet displayed the full colouration pattern of adults. In period of 24 to 29 DPH, the colouration pattern developed with alternating black and yellow stripes running through the entire length of body and the newly settled juvenile measured 12.91 ± 0.35 mm in SL and 3.36 ± 0.12 mm in BD around 30 DPH.

An integrative phylogenomic approach illuminates the evolutionary history of cockroaches and termites (Blattodea)

Phylogenetic relationships among subgroups of cockroaches and termites are still matters of debate. Their divergence times and major phenotypic transitions during evolution are also not yet settled. We addressed these points by combining the first nuclear phylogenomic study of termites and cockroaches with a thorough approach to divergence time analysis, identification of endosymbionts, and reconstruction of ancestral morphological traits and behaviour. Analyses of the phylogenetic relationships within Blattodea robustly confirm previously uncertain hypotheses such as the sister-group relationship between Blaberoidea and remaining Blattodea, and Lamproblatta being the closest relative to the social and wood-feeding Cryptocercus and termites. Consequently, we propose new names for various clades in Blattodea: Cryptocercus + termites = Tutricablattae; Lamproblattidae + Tutricablattae = Kittrickea; and Blattoidea + Corydioidea = Solumblattodea. Our inferred divergence times contradict previous studies by showing that most subgroups of Blattodea evolved in the Cretaceous, reducing the gap between molecular estimates of divergence times and the fossil record. On a phenotypic level, the blattodean ground-plan is for egg packages to be laid directly in a hole while other forms of oviposition, including ovovivipary and vivipary, arose later. Finally, other changes in egg care strategy may have allowed for the adaptation of nest building and other novelties.