Department of Entomology & Nematology
University of Florida, Gainesville, FL 32611-0620
April 17, 1998
- Download and print Chapter 33: Longest[12kb pdf]
Using any criterion of measurement, certain walking sticks (order Phasmida) are the longest insects on earth. Of the phasmids, the champion is a female Pharnacia serratipes that measured 555mm (nearly 22 inches) from extended fore tarsi to extended rear tarsi.
The world's longest insect is indisputably from the order Phasmida (stick insects). In fact, two different Phasmida specimens have been identified as the longest insect on record. Length determination for both of these insects has been made in two ways. The first, by measurement of the insect's body length, excluding the length of the legs. The second, by incorporating the insect's body length and extended leg length from the terminal end of the fore tarsi to the terminal end of the rear tarsi (Bragg 1995). Employing the latter method reveals that there is one definitive winner.
Secondary literature was examined: general entomology as well as natural history and biological texts were researched in order to determine candidates for "longest" insect. Additionally, entomology professors at the University of Florida were consulted. It was determined that the order Phasmida contained all possible candidates.
Study of the primary literature revealed two candidates for longest insect. Of these two, a Pharnacia serratipes from the Malay Peninsula is the champion (Seow-Choen 1995). The second candidate was a specimen of Pharnacia kirbyi from Borneo. Although, misidentified for many years, this insect was the record holder before the discovery of the Malaysian specimen.
The specimen originally identified as the longest insect on record held that distinction for nearly a century. This walking stick was identified by Kirby in 1896 as Pharnacia serratipes. Eight years later, Kirby identified the same specimen as Pharnacia maxima (Bragg 1995). However when Bragg (1995) examined the insect, he concluded that it was actually Pharnacia kirbyi, as described by Brunner in 1907.
Bragg measured this 99 year old walking stick and determined that it had an overall length, including legs, of 546mm, which indeed made it the longest insect on record. However, a more recent discovery of an even longer specimen was made by Seow-Choen (1995). The insect was discovered alive soon after it molted to adulthood. Measurement of the insect after some time in captivity determined that the insect had an overall length of 555mm (nearly 22 inches).
The species of stick insects that reach the incredible lengths recorded here are primarily found in Indonesia. It is possible that there are other living specimens which may surpass the length of the present record holder. However, until a new candidate is identified, the clear winner for longest insect is the West Malaysian Pharnacia serratipes at a length of 555mm.
I would like to thank Dr. Walker for his invaluable information and research assistance.
- Bragg, P.E. 1995. The longest stick insect in the world, Pharnacia kirbyi (Brunner). Entomologist. 114:26-30.
- Seow-Choen, F. 1995. The longest insect in the world. Malayan Nat. 48:12.