Mating with castrated males induces females to oviposit
As I was picking up rotting fruit from the ground, a woman walked by and told me “pick the nice ones from the tree, you are going to get sick”. I was amused by her concern and explained that indeed I was looking for the rotting fruit. I was searching for the fly maggots that infest oranges and mangoes.
The Mexican fruit fly is a pest that can cause devastating effects for both small fruit farmers and exporters. Most people think of fruit flies as those pesky small flies around our ripening bananas, but those in reality are in the Family Drosophilidae, the vinegar fruit flies. The pests that I was looking for are called the true fruit flies and belong to the Family Tephritidae. The reason for this distinction is that the true fruit flies lay their eggs in fruits when they are still green on the tree, while the vinegar flies lay their eggs in ripening or rotting fruit. The eggs of the true fruit flies develop into maggots (larval flies) which eventually leave the fruit when it falls from the tree. Once on the ground, the maggots burrow into the soil and form a cocoon known as a pupa. Some species even have an unusual behaviour in which the maggots can coil and jump from the fruit into the soil. A few weeks later the adult emerges from the pupa; eats and matures sexually; mates; and then lay eggs into the fruit.
Some species from the Tephritidae are worldwide pests that cause huge losses in agriculture and commerce. Because no one wants to eat fruit with maggots inside, scientists have developed various control measures against these flies. One of the most successful and environmentally friendly means of control is called the Sterile Insect Technique (SIT). This technique begins with mass-rearing of the insect in huge factories. Then the males are sterilized (so they cannot reproduce) and are released into the field where they will mate with the wild females. These mated females will not be able to lay fertile eggs in the fruit and so the number of flies in the next generation decreases. So SIT uses the pest as a type of its own “birth control” and reduces the use of harmful insecticides. By avoiding pesticide use, this method has the advantage of not targeting beneficial insects such as native bees.
For SIT to be effective, we need factory-produced males to be attractive to wild females and to successfully prevent the females from mating with other wild males that may be around. In my lab we are trying to understand how males that mate with females can cause the females to not mate with other males, and this has led us to studying the male ejaculate. It turns out that when males mate, they transfer to the female not just sperm, but a whole lot of other substances from the male accessory glands (MAGs). In many insects, these glands contain proteins that act as anti-aphrodisiacs, so that when females receive them after mating, they will not remate. The gland contents also stimulate the female of other species into laying more eggs. These are all very important behaviours when it comes to pests, as we do not want them to lay fertile eggs or mate again. The Mexican fruit fly has very complex male accessory glands, thus we are trying to find out what effect they have on the females. By injecting the contents of the MAGs into females, we observed that, contrary to what happens in other insects, they did not increase egg laying. So, the question still remains as to what the functions of Mexican fruit fly MAGs are.
Next, as the MAG contents do not increase egg laying, we wanted to find out about the whole ejaculate (MAG contents and sperm plus other components). Thus, we proceeded to cut the tip of the male penis (don´t worry they could still mate), so that they could not transfer any of their ejaculate. Surprisingly, we found that females that mated with these partially castrated males laid more eggs compared to virgin females that did not mate. This means that the internal and external aspects of the male copulatory courtship behavior that females receive during the mating is enough to stimulate them to lay eggs.
These results are important for two reasons: 1) studying MAGs can help us better develop control measures for these pests, with a better understanding on how mating affects female behaviour, and 2) we still know little about how various stimuli during mating affect female reproduction. As these are pests of economic importance to fruit growers, this knowledge will help us to further improve an environmentally friendly means of control.
On June 8th, we invite you to celebrate National Insect Appreciation Day (NAIAD) with thousands of insect enthusiasts, amateurs, and professionals all across Canada. For a second year, because of the COVID-19 pandemic, the celebrations will take place online. Hence, it will still be possible to participate in the “insect picture challenge” on social media. We hope that this challenge will prompt the public to develop their curiosity towards insects and raise awareness about the presence of insects all around us.
In order to participate in the challenge, a person will have to post a least one picture of an insect during the National Insect Appreciation Day on June 8th. When posting the photo, the participant should include associated hashtags and nominate five friends by inviting them to also post an insect picture.
How a hashtag works:
A hashtag makes it possible for other users to easily find messages and post with a specific theme or content. Simply use the hashtag on social media (Facebook, Instagram or Twitter) and make sure that your photograph is public.
For more information, and to download resource material, go to:
The ESC Science-Policy committee would like to draw your attention to the following call for expressions of interest for the Workshop on a Canadian Biodiversity Observation Network (CAN BON), due May 31st:
This call is for interested members to be involved in a federally-funded workshop. The main objectives of this workshop will be to:
obtain initial information on the state of biodiversity monitoring in Canada and the resources currently available to support monitoring
identify ways that a CAN BON could support local, regional, national and international efforts to conserve and restore biodiversity, including meeting Canada’s international commitments under the Convention on Biological Diversity
initiate an inclusive approach to the design and implementation of a CAN BON drawing on perspectives from Indigenous peoples, scientists, government, private and public sectors—for Indigenous peoples, the expectation is to pursue a co-development approach to CAN BON that would allow equitable and meaningful participation of Indigenous peoples and a weaving of traditional knowledge and Western science
Eligible groups include Canadian institutes, networks, or teams (including federal, provincial and territorial government groups) who are currently undertaking significant biodiversity monitoring activities and related research
Given the diversity and abundance of terrestrial invertebrate species in Canada, the ESC Science-Policy committee would like to encourage as many eligible groups as possible from ESC membership to apply to attend this workshop. Invertebrates are often neglected in monitoring efforts and resource allocation and, by having more representation at this workshop, there may be an opportunity to advocate for better taxonomic coverage and consideration in the future.
If you do choose to apply, please fill out this google form so we can keep track of the number of groups applying that could represent terrestrial invertebrates at this workshop. These results will be used for internal ESC purposes only. https://forms.gle/pYBX7z7xMJapSnQq7
http://esc-sec.ca/wp/wp-content/uploads/2017/01/ESC_logo-300x352.png00Cass Chowdhuryhttp://esc-sec.ca/wp/wp-content/uploads/2017/01/ESC_logo-300x352.pngCass Chowdhury2021-05-10 18:29:082021-05-10 18:34:36Call for Expressions of Interest: Workshop on a Canadian Biodiversity Observation Network
25-28 May 2021 Shaping Forests: Action in a Changing World
We are proud to announce that the final program has been published and is now available for your viewing pleasure!
Registration is now OPEN with early bird registration occurring until May 1!
Please visit the NAFIWC website to register!
Student Competition Judges: We are currently in search of nine judges for three sessions of student paper competitions all on Wednesday May 26th!
If you are able, please contact Kier Klepzig (email@example.com) or Rich Hofstetter (firstname.lastname@example.org).
The NAFIWC 2021 Proceedings will be published as a USDA Forest Service General Technical Report, publicly available online. All presenters (talks and posters) are encouraged to submit a short synopsis of their work (1-3 pages maximum, including tables and figure as appropriate) for publication in the proceedings. Reports and abstracts will not be edited so please take care to provide a quality document. Please send submissions via email to Deepa Pureswaran at email@example.com by May 25. Submitted abstracts will be used lieu of synopses if not received by the deadline.
Check this site often, we will be announcing training sessions for virtual presentations for moderators and speakers soon!
http://esc-sec.ca/wp/wp-content/uploads/2017/01/ESC_logo-300x352.png00Cass Chowdhuryhttp://esc-sec.ca/wp/wp-content/uploads/2017/01/ESC_logo-300x352.pngCass Chowdhury2021-04-07 18:54:572021-04-07 18:58:252021 North American Forest Insect Work Conference
The 1st International Electronic Conference on Entomology (IECE)
A free virtual event held from 1st–15th July 2021
This event will solely be an online proceeding that allows participation from all over the world, with no concerns of travel or related expenditures, while at the same time, allowing the rapid dissemination of global advances in the study of insects among the entire scientific community. All proceedings will be held online at https://sciforum.net/conference/IECE.
Through this event, we aim to cover the following topics:
Systematics and Morphology
Genetics and Genomics
Biology, Behavior and Physiology
Biodiversity, Ecology and Evolution
Forest and Urban Entomology
Medical and Veterinary Entomology
Apiculture and Pollinators
The conference is completely free of charge—both to attend and for scholars to upload and present their latest work on the conference platform.
IECE is a virtual conference sponsored by Insects (IF: 2.220, ISSN 2075-4450). Participation is free of charge for authors and attendees. The accepted papers will be published free of charge in the journal Proceedings of the conference itself.
IECE offers you the opportunity to participate in this international, scholarly conference without the concerns or expense of traveling—all you need is access to the Internet. We would like to invite you to “attend” this conference and present your latest work.
We look forward to receiving your research papers and to welcoming you to the 1st International Electronic Conference on Entomology (IECE). Please do not hesitate to contact us if you have any questions.
Prof. Dr. Nickolas G. Kavallieratos
Chair of the 1st International Electronic Conference on Entomology