Hum­ming along: The most beautiful moth

Manitoba Gardener Magazine - - CONTENTS - By Sharon Mof­fat

Spend­ing time in the gar­den is al­ways a won­der­ful way to en­joy na­ture and very oc­ca­sion­ally one may be for­tu­nate enough to spot one of our more dra­matic and beautiful moths, the hum­ming­bird moth. Sim­i­lar in size to their name­sake birds they can also be found hov­er­ing at flow­ers when feed­ing on the nec­tar with their ex­tended pro­boscis. Un­like most moths, their wings are quite nar­row and they are some of the fastest fly­ing in­sects around. While the ma­jor­ity of moths fly about dur­ing the night­time, hum­ming­bird moths are day­time fliers. Also like hum­ming­birds, they beat their wings very rapidly which adds to the like­li­hood of mis­tak­ing them for the birds they are so aptly named af­ter.

Hum­ming­bird moths are in the Sph­ingi­dae fam­ily of moths which in­cludes var­i­ous species of sphinx and hawk moths. These very large moth species are al­ways a treat to en­counter, un­less of course you’re not a fan of moths.

The cater­pil­lars of hum­ming­bird moths are also very large and find­ing one in the gar­den can be startling. Typ­i­cally, the cater­pil­lars are a bright green, thick-bod­ied and a few inches in size; about the size of an adult’s finger. Smooth with only a few scat­tered hairs, they can be fur­ther dis­tin­guished by what’s re­ferred to as a horn at the top end of their body, re­sult­ing in the cater­pil­lars be­ing called horn­worms. While this horn can ap­pear dan­ger­ous, it is not and is usu­ally softer than it looks. Most of­ten the cater­pil­lars are first no­ticed when they are look­ing for a place to pu­pate in the fall. At that time they typ­i­cally fall to the ground and crawl to a suit­able spot which is usu­ally un­der leaf lit­ter or just be­low the sur­face of the soil. In Canada, there is most of­ten only one gen­er­a­tion per year. It is the pu­pal stage that over-

win­ters. Adults emerge in the spring, mate and lay eggs that then hatch and feed on plants through­out the sum­mer months.

The cater­pil­lars pre­fer to feed on plants like hon­ey­suckle, hawthorn, snow­berry and plants in the prunus genus which in­cludes many of our fruit trees. While these large hum­ming­bird cater­pil­lars (horn­worms) are vo­ra­cious and can con­sume a large quan­tity of plant ma­te­rial, there usu­ally aren’t many of them at any given time. As a re­sult, the use of chem­i­cals to con­trol them isn’t of­ten nec­es­sary. And be­cause they are so large, it is quite easy to see them and sim­ply pick them off any plants that are be­ing un­duly dam­aged. Oc­ca­sion­ally larger num­bers may oc­cur or they may find smaller veg­etable or flow­er­ing plants that would be quickly de­voured if left unchecked. In these cases, the bi­o­log­i­cal in­sec­ti­cide BTK ( Bacil­lus thuringien­sis kurstaki) can be used to suc­cess­fully con­trol them.

It is im­por­tant to re­mem­ber that hum­ming­bird moths are pol­li­na­tors like many other in­sects and they will use their long pro­boscis to drink the nec­tar from a wide va­ri­ety of flow­ers, sim­i­lar to flow­ers that hum­ming­birds would feed from. When feed­ing on nec­tar, they will brush against pollen that will be­come at­tached to their bodies and be trans­ferred to other plants. So while the large, vo­ra­cious cater­pil­lars may be a bother, the adults are com­pletely ben­e­fi­cial with the added bonus of be­ing beautiful to look at.

Sharon Mof­fat has a Plant Sci­ence de­gree and works for the City of Win­nipeg's In­sect Branch.

Hum­ming­bird moths, so named be­cause they share the abil­ity to hover in the air like hum­ming­birds.

Hum­ming­bird clear­wing moth.

Cater­pil­lars are also known as horn worms, due to their harm­less "horn".

Newspapers in English

Newspapers from Canada

© PressReader. All rights reserved.