Commercial butterfly breeders: industry has vested interest in raising OE-free butterflies

NOTE:  The following guest post by Dr. Barbara Dorf* arrived as a lengthy comment here at the Texas Butterfly Ranch last week.  I invited Dorf to expand her comment to a full-blown post because I think the perspective of professional breeders is important to various issues discussed here.

–Monika Maeckle

As a board member of the Association for Butterflies, an organization for about 80 professional and hobbyist butterfly breeders and a co-owner of Big Tree Butterflies  commercial butterfly breeding farm,  I am writing today to clarify our position in relation to the proposed petition to the U.S Fish and Wildlife Service (USFWS) to list the Monarch butterfly as threatened or endangered under the Endangered Species Act (ESA).

Barbara Dorf and Tracy Villareal, owners of Big Tree Butterfly Farm in Rockport, Texas --Courtesy photo

Dr. Tracy Villareal and Dr. Barbara Dorf, owners of Big Tree Butterflies in Rockport, Texas –Courtesy photo

As stated in a recent post on this website, Lawsuit seeks ESA monarch butterfly listing, turns up heat on commercial breeders, the petitioners believe that commercial breeders release diseased butterflies into the wild population, potentially damaging it.  Such comments oversimplify the butterfly industry and misrepresent the efforts of many breeders who are very diligent and dedicated to raising healthy butterflies.

Butterfly disease is a concern for all ethical butterfly breeders and part of the larger issue of raising healthy butterflies in captivity. Our concern is at several levels.

We want to raise healthy butterflies and provide customers with the best value for their money. In addition, butterflies are living creatures and proper animal care practices need to be observed. Failure to adopt clean rearing procedures is costly and ultimately self-destructive. That said, there are areas of concern.

Ophyryocystis elecktroscirrha, or OE, has been studied extensively and is of particular concern because it can significantly impact Monarch populations. It is the most commonly mentioned disease problem in both the butterfly industry and popular press. OE occurs in nature, primarily infecting Monarchs and related butterflies. It is found in Monarch butterfly populations throughout the world, including North and South America, the Caribbean, Hawaii, and Australia.

OE spores transfer through physical contact or consumption of milkweed leaves. PHoto courtesy AFB

OE spores transfer through physical contact or consumption of milkweed leaves. Photo by Dr. Tracy Villareal

OE can be transmitted in two ways. In nature and during captive breeding, spores are transmitted from egg-laying females to their offspring when dormant spores on the female’s body scales are scattered on eggs or as they are passed onto milkweed leaves that are the Monarch’s only host plant. Newly emerged caterpillars consume spores when they eat their eggshell or when feeding on milkweed leaves. Spores can also be spread between adults through body contact, more likely to occur during captive breeding when adults are kept in higher concentrations than in the wild.

Once eaten, the spores have a rather complicated life cycle, with the end result being many more spores, which are often visible inside the chrysalis. When the butterfly emerges spores are located mostly on the abdomen.

OE can be debilitating, often killing or deforming caterpillars, chrysalises and adults. Infected adults have been shown to be smaller, have shorter lives, and mate and migrate less successfully. However, those that do mate can continue to lay eggs, passing on the OE spores to the next generation, both in nature and in captivity.

deformed Monarch OE

OE infected Monarchs can have trouble emerging from the chrysalis and may be deformed. Photo via UGA Monarch parasites website

If not controlled, all butterflies within a captive breeding colony will become infected with OE in very few generations, resulting in poor quality butterflies unable to successfully breed or migrate when released. This is a butterfly breeder’s worst nightmare.

Thus, the butterfly industry has a vested interest in producing OE-free butterflies and educating all breeders on how to produce healthy butterflies. The problem is not that all butterfly breeders raise and sell OE-contaminated Monarch butterflies. Rather, the problem is that customers cannot tell if the butterfly breeder they are purchasing from raises OE-free butterflies.

The AFB has been implementing programs over the last 10 years and has been anything but lethargic concerning OE in commercially raised butterflies.

Here is what the AFB is doing to address the problem:

1. Educational programs

The AFB offers educational programs developed by butterfly professionals and academic researchers available to anyone who wants to learn more about butterfly disease prevention.

Our annual “Disease Prevention in Lepidoptera” course (offered for the last 10 years!) is free to all members and has been taken by hundreds of professional breeders, hobbyists, enthusiasts and educators, and offers a Disease Seal and certification for participants who successfully complete weekly testing and a final exam.

2. Disease screening co-op

In addition to education, the AFB also offers its members a 3rd-party Disease Screening Co-op in conjunction with the Mississippi State Pathology Department.  Caterpillars are screened by pathologists for viruses, bacteria and parasites, helping breeders to detect issues in breeding butterflies before disease can cause serious issues.

3. OE Clean Screen Program

The AFB has initiated the OE Clean Screen Program, a butterfly industry first. This is a 3rd-party OE testing program in which professional breeders voluntarily submit Monarch chrysalises to an independent University laboratory for OE testing when the adult butterfly emerges. Submitting fresh chrysalises eliminates any possibility of “selection” for OE-free AFBlogo

butterflies. Acceptable OE levels reflect natural background levels, with 20% of all butterflies tested having either no OE or showing light contamination (less than 100 spores). The program was set up with comments and advice from Dr. Sonia Altizer, a leading Monarch butterfly researcher and world-expert on OE.

Testing is voluntary and anonymous. Breeders will receive a Clean Screen rating and be highlighted on the AFB website as part of a Preferred Listing. The rating indicates that the breeder has met standards for OE prevention that have been approved by academic researchers. No program with this level of rigor and independent evaluation has ever been attempted. This is a serious program to address a legitimate concern. It is open to all butterfly farmers, even if they do not belong to the AFB.

The purpose of this testing program is not to penalize breeders who may have OE-positive butterflies, but to get a better picture of the butterfly industry, offer support and education, troubleshoot, identify, and correct possible rearing problems, and to encourage all butterfly breeders to do a better job of keeping a clean operation. The result will be that customers will be able to compare butterfly breeders based on this independent standard. The marketplace will determine the rest. Independent, 3rd-party certification allows customers to know that the breeder was producing Clean Screen stock at the time and that they are taking an active interest in producing healthy butterflies. Thus, it is in the butterfly breeder’s best interest, once they have Clean Screen stock, to maintain them.

There are unscrupulous butterfly breeders out there who do not practice clean breeding techniques and give the entire butterfly industry an unfavorable image. Because these unscrupulous breeders exist, buying butterflies from breeders engaged in independent 3rd-party testing allows customers to know that they are buying from a butterfly breeder who is seriously working to produce healthy butterflies.

In closing, butterfly disease is a concern for all ethical butterfly breeders and the AFB is working hard to provide the best possible support to butterfly breeders for rearing healthy butterflies.

*When she’s not raising butterflies, Barbara Dorf works as a fishery biologist at Texas Parks and Wildlife.  She earned her PhD in biological oceanography at the University of Rhode Island and holds undergraduate degrees in wildlife and fisheries science and aquatic biology.
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