The Third Season of Song: Insects
By Mary Gartshore
The frogs finished singing back in July and most songbirds have stopping singing with the exception of year-round residents such as Northern Cardinal and Carolina Wren. Now the crickets, katydids and cicadas are engaged in the third season of song. I will focus on katydids. The natural corridor along the Lynn Valley Trail offers excellent habitat for all of our singing insects offering photography and sound recordings to the visitor. Around July 12 the rare Species-At-Risk flightless Davis’s Shieldback (Fig.1) starts to sing its quiet “suffling” song. It was first discovered in Canada by the researcher Tom Freeman from the Canadian National Collection in 1937 on his family farm now Simcoe’s industrial park on Luscombe Drive.
Oblong -winged Katydid (Fig.2) that calls “squeeze-it” at night in plain sight on top of vegetation. In late July the first conehead starts to sing and sounds like maracas playing in ditches and meadows. In early August the southern species Northern True Katydid adds to the chorus. Its song is a raucous “ret-ret-ret” also known locally as the “back-ache” bug. The Northern True Katydid has large rounded wings but cannot fly, instead wings are a sounding chamber. It has the reputation of being the loudest singing insect in North America.
Now at the beginning of September, little tree crickets are in full swing. Tree Crickets include Pine, Snowy, Temperature, Black-horned, Four-spotted and Two-Spotted. Pine has a clear sweet tone with no pulses and can be heard during the day, the moment one steps into a pine plantation. Snowy has a low pitched 10-second “drrrrrrr”. At night male Temperature Crickets synchronize a sweet pulsed “drrr-drrr-drrr…” continuously. Count the number of pulses in 15 seconds and add to 40 to give you the temperature in Fahrenheit degrees. Black-horned and Four-spotted Tree Crickets (Fig.4) are very common in open fields. Both have sweet trills. The four spots on the latter are on the front of the lowest segment of each antenna. Two-spotted Tree Cricket (Fig.3) is a newcomer. There were no Canadian records up to 1985 when Part 14 of Agriculture Canada’s Insects and Arachnids on Orthoptera (grasshoppers) was published. Then suddenly in 2013 people were noticing them at their porch lights. Now they are abundant throughout southern Ontario. I speculate that the unusually warm summer of 2012 allowed insect species to colonize areas to the north.
Tree cricket males sing to attract females for mating. Male tree crickets create their songs by holding their wings vertical to their bodies and rubbing them together. Under their fanned wings are two glands that excrete a sugary drink for arriving females. Females sample the drink before deciding to mate (female on top and male below). Females may choose to just sample and leave.
In October the Retuse Conehead (Fig.5) finally matures and begins to buzz softly. It sits on grass stems or Common Ragweed. When approached it drops into the grass and just disappears. There are only a few records around Walsingham but worth searching for them elsewhere in southern Ontario. Their large relative called the Robust Conehead is a rare prairie species occasionally heard in Ontario. Its buzzing call has a pulse rate of around 240 per second. That is one of the fastest muscle contractions for any living animal and has attracted the attention of nanotechnologists.
About the Author, Mary Gartshore
I grew up on a livestock farm with a large forest in the Dundas Valley, where I was encouraged by my parents to explore nature. I graduated in Hons. Zoology, Guelph in 1973. I have carried out biological inventories in Canada, Nigeria, Cameroon, Ivory Coast and elsewhere. In 1990, with partner Peter Carson, purchased a 80ha farm in Norfolk County. Currently, we focus our efforts on nature conservation and ecological restoration in southern Ontario.