Aedes Mosquitoes: The Universal Vector
Jagriti Narang, Manika Khanuja in Small Bite, Big Threat, 2020
Aedes are known as indoor breeding mosquitoes, that is, they breed in freshwater containers usually found inside or around human dwellings (domestic and peri-domestic containers, respectively). For laying eggs in foci favorable within these dwellings, the females search for damp or moist places that form little water bodies (Gubler, 1989). The preferable sites where eggs are seen are the water collected in tree holes, on the edges of artificial containers such as cement, clay, metallic, and plastic tanks. (Fig. 1.3). They lay around 50–100 eggs at one time. The eggs when laid appear white but change to black as they meet the atmosphere after 2 h (Nelson, 1986). They are oval shaped, covered with shell, and 1 mm in length (Fig. 1.4). The shell is partly secreted by the mother and partly by the embryo. They are soft and flexible when laid but later become hard and waterproof. The embryo develops inside the eggs within 2–3 days depending on atmospheric conditions. These eggs can remain viable up to a year (Foster and Walker, 2002). If an infected female has laid the eggs, then there are chances of the progeny getting infected; in other words, the female is capable of vertical transmission (egg to progeny). The process of laying eggs at a suitable place is termed oviposition, and this is done with the help of fine sensory hairs present on the lower parts of the abdomen (Clements, 2000).
Population and Community: Count Variables
Song S. Qian, Mark R. DuFour, Ibrahim Alameddine in Bayesian Applications in Environmental and Ecological Studies with R and Stan, 2023
We explore the multinomial response variable model through three examples. The first example is developed based on a study of insect oviposition behavior in evolutionary ecology. The data for this example includes observed number of eggs laid by a species of wasp. This species of wasp is an insect parasitoid, which lays eggs in or on the eggs, larvae, pupae, or adults of other insects. The number of eggs they laid in each host is known as the clutch size. Some parasitoids are used for biological control of insect pests in orchards and other agricultural settings. On the one hand, the number of eggs laid in a host can affect the survival and fitness of the offspring. The ecological hypothesis is that the clutch size is evolved to produce the maximum number of offspring from each host that are fit to further propagate the population. Too many eggs will lead to competition among offspring for the limited resource (reducing the fitness of offspring), too few eggs constitutes a waste of the resource. On the other hand, the number of eggs a parasitoid lays in a single host can be affected by other factors. It takes time and effort for a parasitoid to find a host and then locate suitable spots on the host to lay eggs. Laying too few eggs would cost the parasitoid time and energy. Hilborn and Mangel [1997] used data from an observational study of a number of wasps to learn whether the clutch size is also a function of numbers of eggs each insect carried (egg complements).
Some Case Histories
Jacques Derek Charlwood in The Ecology of Malaria Vectors, 2019
In addition, a number of fundamental questions regarding the ecology and behaviour of the mosquitoes were posed. In particular, we attempted to determine if post-oviposition behaviour was environmentally determined or was intrinsic to the particular species and, if it was environmentally determined, what was responsible for the differences in behaviour. The factors that make A. dirus such a potent vector were also investigated.
Radiation biology of a serious tropical pigeon pea pest, Maruca vitrata (Fabricius) (Lepidoptera: Crambidae) and potential of radiation mediated ‘inherited (F1) sterility technique’ for the pest suppression
Published in International Journal of Radiation Biology, 2020
Rakesh K. Seth, Basavaraj V. Patil, Zubeda Khan, Mahtab Zarin, Shivanand G. Hanchinal, Rachappa V. Haveri, Akshatha Gopalkrishna
Various reproductive parameters were assessed by pairing treated insects with normal counterparts up to the next filial generation. The irradiated P1 males, treated with 100 Gy, 150 Gy, 200 Gy, or 250 Gy, were crossed with normal females. A control group (0 Gy) of unirradiated males mated with unirradiated females was run concurrently with treated regimens. The ovipositional behavior was monitored in terms of pre-oviposition and oviposition period and total number of eggs laid per female. The per cent fertility was assessed by recording the number of eggs hatched out of total number of oviposited eggs for each regimen. The daily profile of eggs being oviposited and their specific day-wise fertility were recorded. To study the reproductive behavior, each experiment was replicated ten times and each replicate constituted four pairs of adults. The sterility was expressed as the percentage of eggs that failed to hatch. Corrected Sterility and Control of Reproduction were computed according to the methods, as detailed below (Seth and Reynolds 1993):
A short guide to insect oviposition: when, where and how to lay an egg
Published in Journal of Neurogenetics, 2019
Kevin M. Cury, Benjamin Prud’homme, Nicolas Gompel
In the final stage of egg laying, eggs are expelled from the uterus and physically deposited in the environment via, the ovipositor. This complex structure is made up of multiple ventral abdominal components originating from different segments (Grimaldi & Engel, 2005). In most winged insects (Pterygota), the shaft of the ovipositor combines different derivatives of the 8th and 9th ventral abdominal segments, organized in appressed bilateral structures and forming a tube or a guide. In contrast to the roughly conserved internal reproductive anatomy, the ovipositor exhibits dramatic diversification across the insect group, adapting to the particular demands of the substrate upon which eggs are laid. Yet, the ovipositor has retained at least one common element throughout insect evolution, a pair of bilateral plates derived from abdominal segment 9, called gonocoxites (Grimaldi & Engel, 2005). From a mere guide to push the egg out, it has become in some species an organ to dig, to drill, or to navigate deep through wood cracks or fruits. The variety and versatility of ovipositors across Insecta are mirrored by the diversity in the number and type of sensory hairs across its surface (Ahmed, Zhang, He, Bai, & Wang, 2013; Belanger & Orchard, 1992; Zhang, Hu, Dou, & Wang, 2012).
Radiation induces stress and transgenerational impacts in the cricket, Acheta domesticus
Published in International Journal of Radiation Biology, 2022
When most crickets have reached sexual maturity (expressed wings), the breeding colony was provided with oviposition mediums in small plastic containers (7 × 7 × 7 cm) (Organic Garden Soil, Swiss Farms Products Inc., Marysville, USA). One container of oviposition medium was left in the colony to collect eggs for 48 h and attracted numerous females for oviposition. Eggs were incubated at 29 °C ± 2 °C and they hatched in approximately 11–13 days. Several replicates of hatchlings were subsequently reared to maturity to ensure quality of experimental crickets.
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